Stockholders' Equity - Changes and Reclassifications Related to Other Comprehensive Income (Loss), Net of Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income, net of taxes	$ 114	$ 159	$ 38	$ 99
Net unrealized gains (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss) before reclassifications			5
Gains reclassified into earnings			(3)
Change in net unrealized (losses) gains on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss) before reclassifications			144
Gains reclassified into earnings			(177)
Change in unrealized components of defined benefit plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss) before reclassifications			(39)
Gains reclassified into earnings			101
Change in cumulative translation adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss) before reclassifications			7
Gains reclassified into earnings			0
Reclassifications of gains (losses) into earnings | Net unrealized gains (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss) before reclassifications	3	0	5	1
Gains reclassified into earnings	0	(17)	(3)	(9)
Other comprehensive income, net of taxes	3	(17)	2	(8)
Reclassifications of gains (losses) into earnings | Change in net unrealized (losses) gains on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income (loss) before reclassifications	111	71	144	(85)
Gains reclassified into earnings	(60)	79	(177)	105
Other comprehensive income, net of taxes	51	150	(33)	20
Reclassifications of gains (losses) into earnings | Change in unrealized components of defined benefit plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income, net of taxes	62	48	62	86
Reclassifications of gains (losses) into earnings | Gains (losses) arising during the period
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains reclassified into earnings	6	0	(39)	1
Reclassifications of gains (losses) into earnings | Amortization of actuarial loss and prior service benefit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains reclassified into earnings	52	46	101	90
Reclassifications of gains (losses) into earnings | Curtailments, settlements and other
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income, net of taxes	4	2	0	(5)
Reclassifications of gains (losses) into earnings | Change in cumulative translation adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other comprehensive income, net of taxes	$ (2)	$ (22)	$ 7	$ 1